Flow velocities of the debris-covered Miyar Glacier, western Himalaya, India

ABSTRACT

Spatiotemporal surface velocity measurements of the alpine valley type debris-covered Miyar Glacier of the Chandrabhaga (Chenab) basin, western Himalaya, were assessed based on the cross-correlation of Landsat images spanning nearly three decades (1992-2019). Long-term (1950-2015) temperature and precipitation trends were evaluated using Asian Precipitation Highly Resolved Observational Data Integration Towards Evaluation (APHRODITE) datasets. The mean velocity (1992-2019) of the Miyar Glacier is ∼29 m/yr, with spatial patterns revealing that the debris-covered tongue is nearly stagnant (∼5 m/yr) compared to the debris-free up-glacier zone (∼35 m/yr). The transition zone from clean to debris-covered ice in the mid-ablation area shows the highest long-term mean velocities of ∼60 m/yr during the observation period, likely resulting from a steep surface gradient and greater ice thickness than the other regions of this glacier. The slow-moving and nearly stagnant debris-covered area reveals the highest amount of surface lowering due to the expansion of supraglacial ponds. Miyar Glacier experiences summer speed-up of ∼67–80% in seasonal velocity compared to winter, interpreted as a result from enhanced basal sliding during summer months due to warmer temperatures inputting more meltwater into the subsurface drainage system. Inter-annual velocity variations are greatest in the upper glacier, with higher velocities observed more frequently in recent decades. Future work should aim to elucidate the causes of this pattern, considering the overall rising air temperature trend in the western Himalaya.

KEYWORDS:

• Glacier velocity
• COSI-Corr
• aphrodite
• debris-covered ice
• subglacial hydrology
• himalaya

Acknowledgment

The first author is thankful to the University Grant Commission, New Delhi (3090/ (NET–DEC.2014) for financial support during field visits in the Himalaya. The authors are grateful to Jawaharlal Nehru University for providing research facilities. Thanks to USGS for providing Landsat and Sentinel data at no cost. A special thanks to the entire COSI-Corr team for freely providing the software. We acknowledge the Department of Science and Technology (DST), Govt of India, for sponsoring the ‘Himalayan Cryosphere: Science and Society’ project (DST–CCP/SPLICE (IUCCCC)), for supporting field comparing and laboratory facilities. We thank Karin Ebert and two anonymous referees for their insightful suggestions, which considerably improved the earlier version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

Datasets generated in this study can be downloaded from http://doi.org/10.5281/zenodo.4898754

Additional information

Notes on contributors

Suresh Das

Suresh Das is a Ph.D. student in geography at Jawaharlal Nehru University, New Delhi. His research encompasses mapping and monitoring present and past cryosphere changes based on remote sensing, field mapping, and chronological methods. His contributions to this study is the conceptualization of the article, collection and analysis of remote sensing datasets, figure preparations, and writing the original draft.

Milap Chand Sharma

Milap Chand Sharma is a professor of geomorphology at Jawaharlal Nehru University, New Delhi. His research focuses on field-based mapping and monitoring high-altitude Himalayan glaciers, reconstructing past glacial history using chronological methods. His contribution to this study is supervision and reviewing the draft.

Katie E. Miles

Katie E Miles is an associate lecturer of glaciology and remote sensing at Aberystwyth University, United Kingdom. Her research focuses on the internal structure and subsurface hydrology of high-elevation debris-covered glaciers in the Himalaya through field-based measurements such as instrumented boreholes and dye tracing. Her contributions to this study are writing, reviewing, and figure preparations.